<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

(SoNS) School of Natural Sciences

Glucose-appended photocytotoxic iron(III) complexes of a tridentate Schiff base phenolate ligand [Fe(bpyag)(L)](NO3) (1-3), where bpyag is N,N-bis(2-pyridylmethyl)-2-aminoethyl-$\beta$-d-glucopyranoside and H 2L is 3-(2-hydroxyphenylimino)-1-phenylbutan-1-one (H 2phap) in 1, 3-(2-hydroxyphenylimino)-9-anthrylbutan-1-one (H 2anap) in 2 and 3-(2-hydroxyphenylimino)-1-pyrenylbutan-1-one (H2pyap) in 3, were synthesized and characterized. The complex [Fe(dpma)(anap)](NO3) (4), having bis-(2-pyridylmethyl)benzylamine (dpma), in which the glucose moiety of bpyag is substituted by a phenyl group, was used as a control and the complex [Fe(dpma)(anap)](PF6) (4a) was structurally characterized by X-ray crystallography. The structure shows a FeN4O2 core in a distorted octahedral geometry. The high-spin iron(III) complexes with magnetic moment value of ∼5.9 $\mu$B showed a low-energy phenolate-to-Fe(III) charge-transfer (CT) absorption band as a shoulder near 500 nm with a tail extending to 700 nm and an irreversible Fe(III)-Fe(II) redox couple near -0.6 V versus saturated calomel electrode. The complexes are avid binders to calf thymus DNA and showed photocleavage of supercoiled pUC19 DNA in red (647 nm) and green (532 nm) light. Complexes 2 and 3 displayed significant photocytotoxicity in red light, with an IC50 value of ∼20 $\mu$M in HeLa and HaCaT cells and no significant toxicity in dark. The cell death is via an apoptotic pathway, by generation of reactive oxygen species. Preferential internalization of the carbohydrate-appended complexes 2 and 3 was evidenced in HeLa cells as compared to the control complex 4. A 5-fold increase in the cellular uptake was observed for the active complexes in HeLa cells. The photophysical properties of the complexes are rationalized from the density functional theory calculations. {\textcopyright} 2014 American Chemical Society.

World University root node

Chemistry

Inorganic Chemistry

Carbohydrate-appended tumor targeting iron(III) complexes showing photocytotoxicity in red light

We study the effects of top-Higgs anomalous coupling in the production of a pair of Higgs boson via gluon fusion at the Large Hadron Collider (LHC). The introduction of anomalous ttH coupling can alter the hadronic double Higgs boson cross section and can lead to characteristic changes in certain kinematic distributions. We perform a global analysis based on available LHC data on the Higgs to constrain the parameters of ttH anomalous coupling. Possible overlap of the predictions due to anomalous ttH coupling with those due to anomalous trilinear Higgs coupling is also studied. We briefly discuss the effect of the anomalous ttH coupling on the HZ production via gluon fusion which is one of the main backgrounds in the HH → γγb b̄b channel. © 2014 The Author(s).

Physics

Fulltext

Journal of High Energy Physics

TtH anomalous coupling in double Higgs production

Due to the prevalent use of polycarbonate plastics and epoxy resins in packaging materials and paints for ships, there has been a widespread global contamination of environmental water sources with bisphenol A (BPA). BPA, an endocrine disruptor, has been found to cause tremendous health problems. Therefore, there is an urgent need for detecting BPA in a convenient and sensitive manner to ensure water safety. Herein, we develop a fluorescent turn-on BPA probe, named Bisphenol Orange (BPO), which could conveniently detect BPA in a wide variety of real water samples including sea water, drain water and drinking water. BPO shows superior selectivity toward BPA and up to 70-fold increase in fluorescence emission at 580. nm when mixed with BPA in water. Mechanistic studies suggest a plausible water-dependent formation of hydrophobic BPA clusters which favorably trap and restrict the rotation of BPO and recover its inherent fluorescence. © 2014 Elsevier B.V.

Analytica Chimica Acta

"Orange alert": A fluorescent detector for bisphenol A in water environments

The Raman signal enhancement depends mainly on four critical factors. These factors are localized surface plasmon resonance (LSPR) of gold substrates along with shape and electronic absorbance of Raman reporters along with laser sources. Hence, the effects of all these four parameters were systematically studied by changing either the different geometries/shapes of the gold substrates having a wide range of SPR or electronic absorbance of Raman reporters under a fixed laser excitation of 633 nm or 785 nm. Enhancement factor (EF) values were evaluated for each individual substrate with respect to five different Raman reporters which cover the maximum absorbance from 530 nm to 800 nm. The EF values suggest that the signal intensity has been increased by at least ten times compared to previous reports. Among the five different shapes of the gold nanoparticles, the substrate of gold nanostars (GNSt) was found to be the most suitable substrate for the highest signal enhancement under both excitation laser sources. The substrate of gold nanosphere (GNSp) is the second best at 633 nm laser excitation; however it is the modest substrate for SERS enhancement at 785 nm laser excitation. After finding the key tools for the development of ultrasensitive SERS nanoprobes, we selected the best Raman reporter (Cy7LA) for the development of biocompatible SERS nanotags in three different SERS substrates for the effective detection of cancer cells under 785 nm laser source. © 2014 The Royal Society of Chemistry.

RSC Advances

Wavelength and shape dependent SERS study to develop ultrasensitive nanotags for imaging of cancer cells

Chemistry - An Asian Journal

Erratum: Synthesis of privileged scaffolds by using diversity-oriented synthesis (Chemistry - An Asian Journal (2013) 8 DOI: 10.1002/asia.201201203)

Exploration of sustainable alternatives to chemicals derived from petro-based industries is the current challenge for maintaining the balance between the needs of a changing world while preserving nature. The major source for sustainable chemicals is either the natural existing plant sources or waste generated from agro-based industries. The utility of such resources will supplement new processed materials with different sets of properties and environmental friendliness due to their biodegradability and low toxicity during preparation, usage and disposal. Amongst other polymers used on a day-to-day basis, phenolic resins account for vast usage. Replacement of petro-based monomers such as phenol and its derivatives either partly or completely utilized for the synthesis of such resins is ongoing. Extraction of natural phenolic components from cashew nut shell liquid, lignin, tannin, palm oil, coconut shell tar or from agricultural and industrial waste, and their utilization as synthons for the preparation of bio-based polymers and properties obtained are reviewed in this paper. This review article is designed to acknowledge efforts of researchers towards the "3C" motto-not only trying to create but also adapting the principles to conserve and care for a sustainable environment. This review paper describes how extraction, separation and recovery of desired phenolic compounds have occurred recently; how substituted phenol compounds, unmodified and modified, act as monomers for polymerization; and how the presence of sustainable phenolic material affects the properties of polymers. There are about 600 references cited and still there is a lot to uncover in this research area. This journal is © the Partner Organisations 2014.

Naturally occurring phenolic sources: Monomers and polymers

We report an investigation into the magnetic and electronic properties of partially hydrogenated vertically aligned few layers graphene (FLG) synthesized by microwave plasma enhanced chemical vapor deposition. The FLG samples are hydrogenated at different substrate temperatures to alter the degree of hydrogenation and their depth profile. The unique morphology of the structure gives rise to a unique geometry in which graphane/graphone is supported by graphene layers in the bulk, which is very different from other widely studied structures such as one-dimensional nanoribbons. Synchrotron based x-ray absorption fine structure spectroscopy measurements have been used to investigate the electronic structure and the underlying hydrogenation mechanism responsible for the magnetic properties. While ferromagnetic interactions seem to be predominant, the presence of antiferromagnetic interaction was also observed. Free spins available via the conversion of sp 2 to sp 3 hybridized structures, and the possibility of unpaired electrons from defects induced upon hydrogenation are thought to be likely mechanisms for the observed ferromagnetic orders.

Scientific Reports

Graphene supported graphone/graphane bilayer nanostructure material for spintronics

ABO discrepancy refers to incongruence between the results of red cell and serum groupings. One such case is described here; the discrepant results of whose routine ABO grouping led to the diagnosis of common variable immunodeficiency. There was no reaction in the reverse grouping of a young patient presenting with recurrent bacterial infections, pointing towards an absence of antibodies in the serum. Diagnosis was made on the basis of markedly decreased serum immunoglobulin levels and by serum protein electrophoresis showing scanty gamma regions. © 2014 Elsevier Ltd.

Life Sciences

Transfusion and Apheresis Science

A rare case report of chronic variable immunodeficiency divulged by ABO discrepancy

Considering that all natural nucleotides (D-dNTPs) and the building blocks (D-dNMPs) of DNA chains possess D-stereochemistry, DNA polymerases and reverse transcriptases (RTs) likely possess strong D-stereoselectivity by preferably binding and incorporating D-dNTPs over unnatural L-dNTPs during DNA synthesis. Surprisingly, a structural basis for the discrimination against L-dNTPs by DNA polymerases or RTs has not been established although L-deoxycytidine analogs (lamivudine and emtricitabine) and L-thymidine (telbivudine) have been widely used as antiviral drugs for years. Here we report seven high-resolution ternary crystal structures of a prototype Y-family DNA polymerase, DNA and D-dCTP, D-dCDP, L-dCDP, or the diphosphates and triphosphates of lamivudine and emtricitabine. These structures reveal that relative to D-dCTP, each of these L-nucleotides has its sugar ring rotated by 180° with an unusual O4-endo sugar puckering and exhibits multiple triphosphate-binding conformations within the active site of the polymerase. Such rare binding modes significantly decrease the incorporation rates and efficiencies of these Lnucleotides catalyzed by the polymerase.

Nucleic Acids Research

Structural and kinetic insights into binding and incorporation of L-nucleotide analogs by a Y-family DNA polymerase

Although lamivudine and emtricitabine, two L-deoxycytidine analogs, have been widely used as antiviral drugs for years, a structural basis for D-stereoselectivity against L-dNTPs, enantiomers of natural nucleotides (D-dNTPs), by any DNA polymerase or reverse transcriptase has not been established due to lack of a ternary structure of a polymerase, DNA and an incoming L-dNTP. Here, we report 2.10-2.25 {\AA} ternary crystal structures of human DNA polymerase $\lambda$, DNA and L-deoxycytidine 5′-triphosphate (L-dCTP), or the triphosphates of lamivudine ((-)3TC-TP) and emtricitabine ((-)FTC-TP) with four ternary complexes per asymmetric unit. The structures of these 12 ternary complexes reveal that relative to D-deoxycytidine 5′-triphosphate (D-dCTP) in the canonical ternary structure of Pol$\lambda$-DNA-D-dCTP, L-dCTP, (-)3TC-TP and (-)FTC-TP all have their ribose rotated by 180°. Among the four ternary complexes with a specific L-nucleotide, two are similar and show that the L-nucleotide forms threeWatson-Crick hydrogen bonds with the templating nucleotide dG and adopts a chair-like triphosphate conformation. In the remaining two similar ternary complexes, the L-nucleotide surprisingly interacts with the side chain of a conserved active site residue R517 through one or two hydrogen bonds, whereas the templating dG is anchored by a hydrogen bond with the side chain of a semiconserved residue Y505. Furthermore, the triphosphate of the L-nucleotide adopts an unprecedented N-shaped conformation. Our mutagenic and kinetic studies further demonstrate that the side chain of R517 is critical for the formation of the abovementioned four complexes along proposed catalytic pathways for L-nucleotide incorporation and provide the structural basis for the D-stereoselectivity of a DNA polymerase.